reasampler/tests/test_spline_edit.cpp

// Standalone tests for reasampler::instrument::ui::spline_edit — no VST3, no REAPER, no
// framework. Asserts the ONE point-editing grammar both spline consumers route through:
// left-click grabs a node and adds in empty space, right-click deletes, control-click toggles
// hard/smooth, and a click outside the mapping box resolves to nothing unless it lands on a
// node's pick radius (so the popup's inset ring can grab but never add).

#include "../src/core/instrument/ui/spline_edit.h"

#include <cstdio>

using namespace reasampler::instrument::ui;
using namespace reasampler::instrument::engine;

static int g_fail = 0;
#define CHECK(cond) do { if(!(cond)) { \
    std::printf("FAIL line %d: %s\n", __LINE__, #cond); ++g_fail; } } while(0)

static const VelocityCurve::Box kBox{100, 50, 127, 101};

// A three-point curve whose interior node sits well away from both endpoints.
static VelocityCurve threePoint() {
    VelocityCurve c = VelocityCurve::rampDown();
    c.addPoint(64.0, 0.5);
    return c;
}

static void testLeftClickOnANodeGrabsIt() {
    const VelocityCurve c = threePoint();
    const auto px = c.pixelFromPoint(kBox, c.points()[1]);
    const SplineEdit e = resolveSplineEdit(c, kBox, SplineGesture::kLeft, px.x, px.y);
    CHECK(e.kind == SplineEditKind::kGrab);
    CHECK(e.index == 1);
}

static void testLeftClickInEmptySpaceAdds() {
    const VelocityCurve c = VelocityCurve::rampDown();
    // Well away from either endpoint's drawn position and from the traced line's nodes.
    const SplineEdit e = resolveSplineEdit(c, kBox, SplineGesture::kLeft, 160, 60);
    CHECK(e.kind == SplineEditKind::kAdd);
    CHECK(e.index == -1);  // no point yet — the caller creates it
}

static void testRightClickOnANodeDeletesAndElsewhereDoesNothing() {
    const VelocityCurve c = threePoint();
    const auto px = c.pixelFromPoint(kBox, c.points()[1]);
    const SplineEdit hit = resolveSplineEdit(c, kBox, SplineGesture::kRight, px.x, px.y);
    CHECK(hit.kind == SplineEditKind::kDelete);
    CHECK(hit.index == 1);
    // Right-click on empty canvas must NOT add — delete is the only thing the gesture means.
    const SplineEdit miss = resolveSplineEdit(c, kBox, SplineGesture::kRight, 160, 60);
    CHECK(miss.kind == SplineEditKind::kNone);
}

static void testControlClickOnANodeTogglesHardAndElsewhereDoesNothing() {
    const VelocityCurve c = threePoint();
    const auto px = c.pixelFromPoint(kBox, c.points()[1]);
    const SplineEdit hit = resolveSplineEdit(c, kBox, SplineGesture::kControlLeft, px.x, px.y);
    CHECK(hit.kind == SplineEditKind::kToggleHard);
    CHECK(hit.index == 1);
    const SplineEdit miss = resolveSplineEdit(c, kBox, SplineGesture::kControlLeft, 160, 60);
    CHECK(miss.kind == SplineEditKind::kNone);
}

// The popup draws its box inset inside a border; a click in that ring must be able to GRAB an
// endpoint handle (which is drawn on the box edge, within the pick radius of the ring) but must
// never ADD — an added point there clamps onto an endpoint's x and stacks an undeletable
// duplicate.
static void testOutsideTheBoxGrabsButNeverAdds() {
    const VelocityCurve c = VelocityCurve::rampDown();
    const auto first = c.pixelFromPoint(kBox, c.points()[0]);
    const SplineEdit ring =
        resolveSplineEdit(c, kBox, SplineGesture::kLeft, first.x - 3, first.y - 3);
    CHECK(ring.kind == SplineEditKind::kGrab);
    CHECK(ring.index == 0);
    // Far outside, on no node at all.
    const SplineEdit away = resolveSplineEdit(c, kBox, SplineGesture::kLeft, kBox.left - 60,
                                              kBox.top - 40);
    CHECK(away.kind == SplineEditKind::kNone);
}

static void testDegenerateBoxResolvesToNothing() {
    const VelocityCurve c = threePoint();
    CHECK(resolveSplineEdit(c, VelocityCurve::Box{0, 0, 0, 40}, SplineGesture::kLeft, 0, 0)
              .kind == SplineEditKind::kNone);
    CHECK(resolveSplineEdit(c, VelocityCurve::Box{0, 0, 40, 1}, SplineGesture::kLeft, 0, 0)
              .kind == SplineEditKind::kNone);
}

// The overlay's box is the FULL area — no inset — so the contour spans the sample's whole
// drawn width 1:1 with its time axis.
static void testOverlayBoxIsTheWholeArea() {
    const OverlayArea area{Rect::ltrb(12, 40, 812, 240)};
    const VelocityCurve::Box box = splineOverlayBox(area);
    CHECK(box.left == 12);
    CHECK(box.top == 40);
    CHECK(box.width == 800);
    CHECK(box.height == 200);
}

int main() {
    testLeftClickOnANodeGrabsIt();
    testLeftClickInEmptySpaceAdds();
    testRightClickOnANodeDeletesAndElsewhereDoesNothing();
    testControlClickOnANodeTogglesHardAndElsewhereDoesNothing();
    testOutsideTheBoxGrabsButNeverAdds();
    testDegenerateBoxResolvesToNothing();
    testOverlayBoxIsTheWholeArea();
    if (g_fail == 0) std::printf("spline_edit: all tests passed\n");
    return g_fail == 0 ? 0 : 1;
}